Water is necessary for carrying nutrients to your cells, flushing bacteria from your system, preventing dehydration, and replacing fluids lost from sweating, but you may not need to drink as much as you thought.
Stephen R. Daniels. pediatrician. No. You shouldn't give your newborn water or sugar water. And if you're feeding powdered or concentrated formula to your baby, never dilute it with more than the amount of water called for on the label. Your infant will get all the necessary hydration from breast milk or formula.
You may also want to give your baby a bath more often during the hot summer months just to cool him down or in case he sweats a lot. If you bathe him more than once a day and he is not very dirty, you can give him a bath with just water and no soap.